Disk Winds and Quasar Broad Emission Lines
As matter slowly spirals into a supermassive black hole at the center of a massive galaxy, it can produce the light we call a quasar. The matter forms a thin accretion disk which heats up and gives off blackbody radiation at a range of temperatures. Quasars also show emission lines from ionized gas moving at speeds of thousands of km/s, usually with an overall blueshift. This line-emitting gas is likely to arise in an optically thick, outwardly accelerating wind at the surface of the accretion disk; such winds are likely needed to explain the single-peaked emission lines of quasars. I'll present preliminary results of new models of such winds which aim to reproduce the observed velocity shifts, line shapes, and aspects of the line width distribution in quasars.
Date: Thursday, 12 March 2009 Time: 12:30 Where: Université de Montréal Pavillon Roger-Gaudry, Local D-460 Contact: Pierre Bergeron